Gureyev is one of the originators of propagation-based X-ray phase-contrast imaging and the transport-of-intensity phase-retrieval methods that made it practical; his current work concerns the information-theoretic limits of imaging — how signal-to-noise, spatial resolution and radiation dose trade against one another — and the application of those limits to phase-contrast tomography, ptychography and electron microscopy, including biomedical imaging at clinically tolerable dose. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — the shared intellectual core is the noise-resolution-dose triangle: the same estimation-theory framework that sets the pT/sqrt(Hz) floor of an NV ensemble governs how many photons a phase-contrast image needs. Borderline inclusion (X-ray rather than quantum sensing), kept because the technique is explicitly about pushing resolution past conventional limits.